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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

27244 results found.

  1. GRB 241029A: TRT optical afterglow candidate detection
  2. GRB 241029A: SVOM/GRM observation
  3. GRB 241029A : Detection and localization of a bright long GRB by SVOM/ECLAIRs
  4. Fermi trigger No 751861204: Global MASTER-Net observations report
  5. GRB 241029A: Fermi GBM Final Real-time Localization
  6. EP241021a: Gemini-South detection of optical rebrightening
  7. GRB 241026A: LBT redshift confirmation
  8. GRB 241026A: GECAM detection
  9. GRB 241026A: SVOM/GRM observation
  10. EP241026B: GROWTH-India Telescope optical upper limit
  11. GRB 241025A: Swift/UVOT Detection
  12. GRB 241026A: GROWTH-India Telescope optical observations
  13. GRB 241026A Fermi GBM Analysis
  14. GRB 241026A: Las Cumbres optical detection
  15. EP241026a (GRB 241026A): EP on-board trigger and follow-up observation
  16. GRB 241026A: Swift-XRT refined Analysis
  17. EP 241026b: LBT optical observations
  18. EP241021a: e-MERLIN radio observation
  19. EP EP241026b: Global MASTER-Net observations report
  20. EP241026b: EP detection of a fast X-ray transient
  21. Fermi trigger No 751616906: Global MASTER-Net observations report
  22. GRB 241026A: COLIBRÍ Detection of the Optical Counterpart
  23. GRB 241026A: SAO RAS observations of possible optical afterglow
  24. Fermi GRB 241026A: Global MASTER-Net observations report
  25. GRB 241026A: Swift detection of a burst
  26. Swift GRB241026.95: Global MASTER-Net observations report
  27. GRB 241026A: Fermi GBM Final Real-time Localization
  28. GRB241025A: 1.3m DFOT optical afterglow detection
  29. EP241021a: optical follow-up observations with Xinglong Observatory
  30. ​GRB 241025A: optical photometry from Konkoly
  31. GRB 241025A: GROWTH-India Telescope optical observations
  32. GRB 241025A: COLIBRÍ Detection of the Afterglow
  33. GRB 241025A: Swift-XRT refined Analysis
  34. GRB 241025C: Fermi GBM Detection
  35. GRB 241025A: Fermi GBM Observation
  36. LIGO/Virgo/KAGRA S241009l: Upper limits from Swift/BAT-GUANO
  37. GRB 241025C: Fermi GBM Final Localization
  38. GRB 241025A: GRANDMA and Kilonova-Catcher optical afterglow detections and upperlimits
  39. GRB 241025B: Fermi GBM Final Localization
  40. Fermi trigger No 751563375: Global MASTER-Net observations report
  41. Fermi trigger No 751554401: Global MASTER-Net observations report
  42. EP241021a: Optical and NIR observations of counterpart with the Fraunhofer Telescope at Wendelstein Observatory
  43. EP241021a: Optical and NIR observations of counterpart with the Fraunhofer Telescope at Wendelstein Observatory
  44. EP241021a: optical follow-up observations with the Liverpool Telescope
  45. Fermi GRB 241025A: Global MASTER-Net observations report
  46. Swift GRB 241025A: Global MASTER-Net observations report
  47. EP241025a (GRB 241025A): EP observations update
  48. GRB 241025A : SVOM/VT optical afterglow observations
  49. EP241021a: Liverpool Telescope optical follow-up observations
  50. GRB 241001A: JWST spectroscopic identification of a supernova counterpart
  51. GRB 241025A: NOT spectroscopic redshift of z = 4.20
  52. EP241025a (GRB 241025A): EP on-board trigger and autonomous follow-up observation
  53. GRB 241025A: SVOM/GRM observation
  54. GRB 241025A: TRT optical afterglow observation
  55. Fermi GRB 241024B: Global MASTER-Net observations report
  56. GRB 241025A: Fermi GBM Final Real-time Localization
  57. GRB 241025A: Swift detection of a burst with an optical counterpart
  58. EP241021a: GTC OSIRIS+ spectroscopy of the optical counterpart
  59. GRB 241024B: Fermi GBM Final Localization
  60. EP241021a: No Detection in Fermi-GBM Observation
  61. GRB 241024A: Fermi GBM Final Localisation
  62. EP241021a: VLT/FORS2 redshift z = 0.75
  63. Fermi trigger No 751449953: Global MASTER-Net observations report
  64. EP241021a: KAIT optical observations
  65. EP241021a: EP-FXT follow-up observation update
  66. EP241021a: 1.3m DFOT Optical observations
  67. EP241021a: Optical upper limits with Kinder observations
  68. EP241021a: TRT optical observations
  69. GRB 241018A: SVOM/C-GFT optical observations
  70. EP241021a: NOT likely optical counterpart
  71. EP EP241021a: Global MASTER-Net observations report
  72. GRB241017A: 1.3m DFOT optical upper limit
  73. GRB 241018A: 1.3m DFOT Optical upper limit
  74. GRB 241018A: EP-FXT afterglow detection
  75. EP241021a: GOTO optical upper limits
  76. EP241021a: EP detection of a fast X-ray transient
  77. GRB 241018A: SVOM/GRM observation
  78. GRB 241018A/sb24101802: Mephisto optical upper limit
  79. GRB 241017A/sb24101702: Mephisto optical upper limit
  80. GRB 241018A: BOOTES-4/MET optical upper limit
  81. GRB 241018A: SVOM/VT further analysis and counterpart confirmed
  82. GRB 241018A: GROWTH-India telescope optical upper limit
  83. GRB241018A: XingLong Optical Upper Limit
  84. GRB 241018A: REM optical/NIR upper limits
  85. GRB 241018A: NOT optical observations
  86. GRB 241017A: SVOM/VT follow-up and optical upper limit
  87. GRB 241018A: SVOM/VT follow-up and optical candidate
  88. GRB 241018A: X-ray afterglow candidate observed by MXT
  89. GRB 241016B: Fermi GBM Observations
  90. GRB 241018A: Detection of a bright long GRB by SVOM
  91. GRB241017a: Liverpool Telescope observations of XRT uncatalogued sources
  92. GRB 241001A: EP-FXT afterglow detection
  93. GRB 241017A: GROWTH-India Telescope optical upper limit
  94. GRB241017A: TOO Observations by SVOM/MXT
  95. GRB 241016B: Swift/BAT-GUANO localization skymap of a short burst
  96. GRB 241017A: J-band upper limit from WINTER
  97. Fermi trigger No 750788395: Global MASTER-Net observations report
  98. GRB 241016B: SVOM/GRM observation
  99. GRB241016C: Fermi GBM Final Localization
  100. Fermi Gamma-ray Burst Monitor trigger 750792698/241016730 is not a GRB

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